Abstract
Purpose:
To determine risk factors for severe acanthamoeba keratitis by comparing severe cases with good prognosis cases.
Methods:
We reviewed medical records of 9 cases of acanthamoeba keratitis (4 males and 5 females) referred to Jichi Medical University Saitama Medical Center between May 2005 and December 2011. The mean age of cases was 29, and the mean follow up period was 450 days. One eye that required therapeutic keratoplasty due to cornea perforation and 3 eyes requiring optical keratoplasty were included in the severe group. Five eyes which had good prognosis and a best corrected visual acuity of 1.2 on last visit were classified as mild group. We compared the time required for diagnosis, visual acuity on first visit, the history of steroid eye drops use, cornea scraping times and clinical findings.
Results:
The duration between onset and diagnosis of acanthamoeba keratitis was 330 days in 1 case of severe group, and in all of the other cases was within 30 days. Best corrected visual acuity was 0.01-0.8 in severe group (mean 0.32), and 0.15-1.2 in mild group (mean 0.56). A history of steroid eye drops use was found in 4 eyes (3 with 0.1% betamethasone, 1 with 0.1% fluorometholone) of severe group (100%), and 3 eyes (all with 0.1% fluorometholone) of mild group (60%). Mean number of cornea scraping was 13.8 times in severe group, and 5.6 times in mild group. Keratoprecipitates were found in all severe group eyes during follow up period. One case of severe group was diagnosed with diabetes mellitus at initial examination. We detected Staphylococcus aureus by palpebral conjunctiva culture in 1 case of the severe group which was resistant to topical antibiotics.
Conclusions:
The use of corticosteroids and the presence of keratoprecipitates are possible risk factors of severe acanthamoeba keratitis. Attention is also required in patients with comorbidities such as diabetes mellitus and bacterial infection.
Keywords: 402 Acanthamoeba •
479 cornea: clinical science •
464 clinical (human) or epidemiologic studies: risk factor assessment